1. Field of Invention
The present invention relates to a routing method, and more particularly, to a re-routing method for a circuit diagram.
2. Description of Related Art
In order to achieve the advantages of simplifying the fabrication of electronic devices, reducing the wirings between electronic components, and lowering the fabrication cost, people starts to research on a printing method to replace a wiring method, and thus develops a printed circuit board (PCB), which is also referred to as a printed wire board (PWB). The PCB is an important electronic component for providing wiring connection for electronic devices. A conventional circuit board adopts a process of printing etching resist to form the circuit wirings and diagram, and thus is referred to as the PCB or PWB. Due to continuous miniaturization and refinement of electronic products, most of the current circuit boards employ the method of attaching the etching resist (lamination or coating), and then use an etching process to form the circuit board after exposure and development.
Referring to FIG. 1, FIG. 1 is a schematic view of a conventional PCB 100. When a substrate 110 of the conventional PCB 100 is observed with a high magnification rate, the substrate 110 includes a plurality of warp wires 111 and a plurality of weft wires 112, which form an uneven surface like a fabric weave surface. Therefore, if a pair of the signal lines 120 and 130 is routed on the substrate 110 in a direction parallel to the weft wires 112 (as shown in FIG. 1), the pair of the signal lines 120 and 130 will be affected by the uneven surface when transmitting a pair of signals, and thus have different time delays. Besides, in other examples, when the pair of the signal lines 120 and 130 is routed on the substrate 110 in a direction parallel to the warp wires 111, the pair of the signal lines 120 and 130 also will have different time delays when transmitting a pair of signals. Under the circumstance of the increasing signal speed, different time delays of the pair of signals are susceptible to resulting in signal transmission errors.